With the continuous development of meteorological science and atmospheric research, millimeter wave cloud radar, as an advanced instrument, plays an increasingly important role in cloud detection and atmospheric observation. This article aims to provide an overview of the development history, technical principles, application fields, and challenges faced by millimeter wave cloud radar. Millimeter wave radar perceives cloud microphysical characteristics such as cloud droplet size, distribution, concentration, droplet moisture content, and raindrop velocity by utilizing electromagnetic waves in the millimeter wave frequency band. Its working principle is based on emitting millimeter wave signals into the atmosphere and analyzing the received echo signals, thereby providing valuable atmospheric and meteorological information. This article first reviews the historical development of millimeter wave cloud radar and analyzes the current development status at home and abroad. With the continuous improvement of radar technology and computing power, millimeter wave radar has been able to improve its detection resolution and accuracy, thereby expanding its application fields. In meteorology, millimeter wave radar can be used for precipitation estimation, cloud monitoring, thunderstorm monitoring, storm tracking, and weather forecasting. Millimeter wave cloud measurement radar has broad application prospects in atmospheric science and meteorology research, providing a key tool for us to better understand and predict weather and climate change. Through continuous technological development and research efforts, millimeter wave radar will continue to play an important role in scientific research and practical applications, providing society with more accurate meteorological information and support for addressing climate change challenges.